Apparatus for the preparation of printing blocks



May 16, 1950 M. T. BONDS ET AL 2,508,216

APPARATUS FOR THE PREPARATION OF PRINTING BLOCKS Filed Aug. 8, 1947 2 Sheets-Sheet 1 BYM film THE/R ATTORNEYS M. T. BONDS ET AL APPARATUS FOR THE PREPARATION OF PRINTING BLOCKS Filed Aug. 8, 1947 2 Sheets-Sheet 2 THE/R ATTORNEYS Patented May 16, 1950 APPARATUS FOR THE PREPARATION OF PRINTING BLOCKS Marvin T. Bonds, Orinda, Thomas A. Moore, Oakland, and Ellis D. Miller, Berkeley, Calif.; said Miller assignor to said Bonds and said Moore Application August 8, 1947, Serial No. 767,510

1 Claim.

Our invention relates to the preparation of printing blocks and more particularly to apparatus for the preparation of such blocks.

In the conventional preparation of printing blocks, the engraving or plate is beveled or formed with reduced edges through which the plates are nailed to a base block of wood or other suitable material. When made in this manner, the finished block is left with a shoulder and it has long been the desire of printers to have plates mounted with their edges flush with the edges of the base block 'on which they are mounted.

Attempts at solving this problem by adhesively or similarly securing the plate or engraving to its base block were unsatisfactory as being too slow and uncertain in results, for unless the plate is securely bonded to its base block, printers are hesitant to employ the same in their presses for fear the plates may come off and do considerable damage to the machine;

Among the objects of our invention are:

(1) To provide a novel and improved apparatus for the preparation of printing blocks;

(2) To provide a novel and improved apparatus for adhesively securing printing plates to their base blocks;

(3) To provide a novel and improved apparatus for quickly preparing printing blocks in which the printing plate or engraving is bonded to its base block;

(4) To provide a novel and improved apparatus for securely bonding printing plates or engravings to their base blocks;

(5) To provide a novel and improved apparatus for the preparation of printing blocks in which the printing plates or engravings may be formed with their edges flush with the base blocks to which they are affixed.

Additional objects of our invention will be brought outvin the following description of a preferred embodiment of the same, taken in conjunction with the accompanying drawings Wherein- Figure 1 is a side elevational view of apparatus embodying the features of the present invention;

Figure 2 is a longitudinal view, in section, of the apparatus of Figure 1;

Figure 3 is a fragmentary plan view of apparatus of Figure 1;

Figure 4 is a front elevational view of the apparatus of Figure 1;

Figure 5 is a view, in section, taken in the plane 55 of Figure 1.

"Referringtc the drawings for a detailed description of our invention in its preferred form, we provide a frame I including side rails 3 supported at a suitable elevation by adequately braced legs 1.

Supported from the underside of the side rails is a horizontal conveyor 9 including end rollers H, 13 and a plurality of intermediate rollers l5 spaced from the end rollers and from each other, and enclosed by an endless belt l1. Except for the end roller at the front end of the machine, each of the rollers of this conveyor has its shaft, at each end, anchoredin a bearing block l9 held and maintained against the underside of a side rail of the frame by a bearing yoke 2| affixed to the underside of such rail, and an adjustable clamping screw 23 through the end of the yoke, having its upper end in engagement with the bearing block.

The front end roller of this conveyor is carried in horizontally slidable bearing blocks 25, each extending through a cut-out 26 in its supporting side rail and capable of being horizontally adjusted by means of an adjusting screw 2! through a supporting block 28 in the end of the rail, whereby tension on the belt of this conveyor may be readily regulated.

Supported on the upper side of the horizontal frame is a second conveyor 29 which, like the first conveyor, is formed of end rollers 3 l, 33 and a plurality of intermediate rollers 35 spaced from the end rollers and from each other and enclosed by an endless belt 31. Except for the end roller 33 at the discharge end of the apparatus, each of the rollers of this upper conveyor has its shaft, at each end, anchored in a bearing block 38 which is slidably supported in a bearing yoke M under compression of a coil spring 43 capable of being adjusted by an adjusting screw 45 through the end of the yoke.

The end roller 33 at the discharge end of the machine, like the end roller at the front end of the machine in the lower conveyor, is carried in similar horizontally slidable bearing 41 supported through openings 48 in the side rails of the frame and capable of horizontal adjustment by means of adjusting screws 49 through similar supporting blocks 50 at the ends of the rails.

By means of these adjusting screws, the tension on the belt of the upper conveyor may be regulated.

The bearing blocks of the upper conveyor are positioned in alignment with the bearing blocks of the lower conveyor, whereby the associated rollers are in alignment and function as compression rollers.

Thus the two conveyors are displaced with respect to each other, with the lower conveyor extending toward the front end of the machine,

leaving a portion 5! of its upper belt surface exposed, upon which work to be handled by the apparatus may be placed.

At the rear end of the lower conveyor, in the plane of the upper surface of the conveyor belt of this conveyor, a plate 53 is disposed within the frame, on which the work may be deposited as it leaves the conveyor.

Positive drive is applied to the aligned compression rollers. In accomplishing this, one of the intermediate rollers of the lower conveyor has its shaft extending beyond the bearing blocks at each end thereof. On one end of this shaft, a drive pulley 55 is mounted for belt connection to some power source, while at the other end, the shaft carries a gear 5'! for meshing with a similarly mounted gear 59 on the end of the shaft of the roller above it.

Each of the other compression rollers has its shaft extending beyond one of the side rails of the horizontal frame, and these are all interconnected by chain belt drives 6| between adjacent rollers, with power take-ofi from the aforementioned gear-connected rollers.

Disposed across the front end of the upper conveyor and capable of blocking the entrance between the conveyor belts is a gate 63 made up of a cross-piece E5 of angle iron mounted on a pair of uprights 61 and 69 and carrying a board II or the like. The uprights are spaced the width of the conveyor belts and are disposed behind guide rollers i3 carried by the front legs of the machine.

Beneath the lower conveyor and extending between the front legs of the machine is a crossmember 15. Pivoted to this cross-member at points 16 to each side of its center, are gateoperating levers Tl, the far ends of these levers being connected to the gate uprights by offsets 19, while the adjacent ends of the levers are joined placed on the lower conveyor belt cannot be carried through the machine. This ofiers the operator an opportunity to arrange the Work and assure himself that all is in readiness before releasing the same through the machine. By stepping on the treadle, the gate will be lifted and the work released, Whereas, by bearing down on the gate in its open position, the same may be readily restored to its closing position in preparation for another run of work through the machine.

To facilitate such handling of the gate, it is roughly balanced against the foot treadle so that a minimum of effort is involved in opening and closing the gate in the manner indicated. The friction, under the circumstances, will be sufficient to assure that the gate will remain in either itsopen or closed position in the absence of any operating force applied thereto.

In preparing the work for passage through the machine, either the plate 86 or the block 8'1, or both, may be given a coating of adhesive, then subsequently assembled for the run through the machine, where due to the pressure and timing, an excellent bond between the two components is realized.

As a bonding agent, We prefer a heat-setting adhesive. With this in mind, the time of travel through the machine should be sufficient to assure adequate cooling of the product by the time it emerges from the machine. Inasmuch as the initial portion of the setting period is the more important, the rollers in the rear half of the machine may be spaced farther apart, and such latter rollers may be considered primarily as insurance against any portion of the plate not being properly secured to its block.

Printing plates are rather delicate and readily damaged when subject to mechanical impact, or excessive pressure against a hard surface or foreign object, and accordingly the belts, particularly that one engaging the engraved surface of the plate, should be of a reasonably soft material such as cotton, rubber, asbestos cloth or the like to protect the plate in the event of such contingencies.

Inasmuch as many of the plates are so small as not to be gripped by two pairs of rollers at a time, precautionary measures must be taken to assure that these printing block assemblies approach a pair of rollers in a plane parallel to the plane through the axes of successive rollers, as otherwise a shearing force is apt to be applied to the printing block assembly, sufiicient to break the bond forming between the plate and the base block.

Such parallel approach is assured by mounting between successive rollers of the lower conveyor, smooth or polished plates 88, the same extending preferably from adjacent one roller peak to the other, with its surface but a few thousandths of an inch below the plane of said roller peaks or just sufficient to preclude sagging of the belt without causing the rollers to lose their grip on the belt.

Conceivably, a chain belt on the lower conveyor might avoid the necessity of installing such plates, but the plates are preferred from the Viewpoint of economy.

From the above description of our invention in its preferred form, it will be apparent that the same fulfills all the objects previously recited therefor, and while we have illustrated and described the same in considerable detail, we do not desire to be limited in our protection to such details, except as may be necessitated by the appended claim.

We claim:

Apparatus for bonding printing plates to a base block to form a printing block, said apparatus comprising a pair of endless conveyors, each of said conveyors including end rollers and intermediate rollers spaced from said end rollers and from each other, and an endless belt encircling the same; means supporting said conveyors opposite each other in vertical uniformly spaced relationship by a distance approaching the thickness of a completed printing block and with cerof the rollers of one conveyor in alignment with certain of the rollers of the other conveyor, the lower of said conveyors extending beyond the other toward the front end of said apparatus for receiving printing block assemblies to be bonded; means driving said rollers and belts whereby a printing block assembly may pass therebetween under pressure of aligned rollers: means for adjusting such pressure; means precluding tilting of those printing block assemblies which are of smaller dimensions than the distance between successive rollers, as they pass from one pair of aligned rollers to a succeeding pair, said means including plates disposed horizontally between rollers of said lower conveyor and sufliciently close to the plane of the peaks of said rollers as to support said belt against sagging between said rollers; and gate means disposed across said low- 5 er conveyor in front of said upper conveyor to Number hold work on said lower conveyor until released. 623,281 MARVIN T. BONDS. 709,864 THOMAS A. MOORE. 850,338 ELLIS D. MILLER. 5 1,033,251 1,154,730 REFERENCES CITED 185L709 The following references are of record in the 2,071999 file of this patent: 2,137,505 10 2,176,945 UNITED STATES PATENTS 2,415,355 Number Name Date 304,724 Graft Sept. 9, 1884 352,131 Johnson Nov. 9, 1886 Number 529,535 Smith Nov. 20, 1894 15 2 ,2

Name Date Jennings Apr. 18, 1899 Boenning Sept. 30, 1902 Bolton Apr. 16, 1907 King July 23, 1912 Runne Sept. 28, 1915 Laucks et a1 Mar. 29, 1932 Dike Feb. 23, 1937 Osgood Nov. 22, 1938 Roberts Oct. 24, 1939 Kaufmann Feb. 4, 1947 FOREIGN PATENTS Country Date France Oct. 21, 1927 

